Date: Wed, 6 Mar 2002 12:12:44 -0500 (EST) From: Zhihui Zhang <zzhang@cs.binghamton.edu> To: Peter Edwards <peter.edwards@openet-telecom.com> Cc: "Brian T.Schellenberger" <bts@babbleon.org>, Lars Eggert <larse@ISI.EDU>, "Rogier R. Mulhuijzen" <drwilco@drwilco.net>, Julian Elischer <julian@elischer.org>, freebsd-hackers@FreeBSD.ORG Subject: Re: A weird disk behaviour Message-ID: <Pine.SOL.4.21.0203061209250.6633-100000@onyx> In-Reply-To: <3C8648F5.1EC1E4EE@openet-telecom.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 6 Mar 2002, Peter Edwards wrote: > Zhihui Zhang wrote: > > <snip> > > > ... I also do not read anything during the partial block write, > > and I think the disk controller should not do that either. > > If you do a partial block write, surely at some point the block must be read > in order to preserve that segment of data you are _not_ overwriting? First off, I am not writing through any file system. I access the raw device directly. Secondly, the bytes written are always a multiple of 512 bytes. If one sector is the I/O unit of a disk controller, why should it read anything to prevent overwritten? -Zhihui To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.SOL.4.21.0203061209250.6633-100000>